Method of manufacturing lightweight-type wheels

ABSTRACT

A method of manufacturing lightweight-type wheels in which a strip of sheet steel is embossed with a series of type characters and, during embosure, the strip is bent or indented along a series of transverse lines, between rows of characters, to an extent sufficient to cause the strip to assume a closed, polygonal, tubular shape. The tubular strip is then affixed to a plurality of internal sheet steel reinforcing members for mounting on an operating shaft.

Unite States Patent Zenner 5] Mar. M, 11972 [54] METHOD OF MANUFACTURING 1,572,233 2/1926 Chamberlin ..I0l/l l0 LIGHTWEIGHT-TYPE WHEELS 2,332,826 10/1943 Fryer et al..... ....1 13/116 X 2,589,682 3/1952 Dudis ..l0l/109 [72] Inventor: Walter J. Zenner, 1776 Sherwood Road, 2 57 775 3/195 i 197/49 Des P1311185, 60016 3,277,561 10/1966 loyal ..29/l59 [22] Med Jan. 1970 Primary Examiner-John F. Campbell [21] Appl. No.: 3,064 Assistant Examiner-Victor A. DiPalma Attorney-Kinzer, Dom and Zickert Related US. Application Data [62] Division of S61. No. 683,993, Nov. 17, 1967, Pat. No. [57] ABSTRACT 3,534,632- A method of manufacturing lightweight-type wheels in which a strip of sheet steel is embossed with a :series of type charac- [52] US. Cl ..27/l59 R, 1 13/1 16 D ters and duflng embosure, the strip is bent or indented along a 1 321d 321k 321k series of transverse lines, between rows of characters, to an ex- {581 Field of Search ..29/ 159, 148.4, 475, 482; mm sufficiem to cause the strip to assume a closed, polygonal, 72/335, 3/116 D; 10 /1 93 tubular shape. The tubular strip is then afi'lxed to a plurality of 50-54 internal sheet steel reinforcing members for mounting on an operating shaft. [56] References Cited 5 Claims, 6 Drawing Figures UNITED STATES PATENTS 8/1913 Dement PATENTEDMAR 14 I972 3, M8 n 3A5 lnventwm mm J. Zemner CROSS-REFERENCE TO RELATED APPLICATION This application is a division of copending application Ser. No. 683,993, filed Nov. l7, 1967, now U.S. Pat. No. 3,534,682, issued Oct. 20, l970.

BACKGROUND OF THE INVENTION In the typewriter and printing industry, clean, clear and easily legible printing has been achieved with type-bar machines using hardened steel type pallets made by a hot forging process. Since, in machines of that kind, only one type pallet or type bar is moved in printing a character, the weight of the type carrying member is not important. These machines, on the other hand, have other disadvantages which designers have endeavored to overcome by the use of type wheels.

Type wheel machines have the entire type font carried on a single unitary member which must be moved to effect the printing of a single character. When conventional forged steel type is used in a type wheel, the wheel is, of necessity, quite heavy and the speed of the machine is severely limited. This weight difficulty has been overcome by molding the character printing portion of the type wheel from moldable synthetic resins or plastics. However, while such materials are readily fabricated and provide a lightweight type wheel, type wheels made in this manner are subject to chipping and wear and the copy produced is generally not satisfactory. These molded type wheels have been improved somewhat by electroplating a metallic layer on the molded member. While this improves the wearing quality and the printed copy, the cost of the type wheel is increased without producing copy as good as that produced by forged type pallets.

SUMMARY or THE INVENTION It is a primary object of the invention to provide a new and improved method of manufacture of a type wheel lighter in weight than a molded type wheel and having the advantages of forged steel type.

A further object of the invention is the provision ofa simple and economical method of manufacturing a lightweight type wheel from a unitary strip of sheet steel.

In the method of the present invention, the embossure of type characters and the forming of a polygonal tubular sheet steel structure are effected simultaneously by feeding a sheet of steel into a punch and die set having cooperating surfaces comprising projecting type character forming and strip bending portions on the punch, and type character forming and strip bending recesses in the die. The cooperating type character forming portions stress the strip of steel beyond its elastic limit to emboss the type in transverse rows on the strip and the bending portions stress the strip beyond its elastic limit in transverse lines between the rows of type characters.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary view of a printer showing the type wheel in a cooperative relation to a wheel driver and a paper supporting platen;

FIG. 2 is a transverse sectional view, on an enlarged scale, taken substantially along the line 2-2 of FIG. 1;

FIG. 3 is a sectional view taken substantially on the line 3 3 of FIG. 2;

FIG. 4 is a view looking in the direction of the arrows on line 4--4 of FIG. 3, parts being broken away to illustrate the mounting of the type wheel;

FIG. 5 is a diagrammatic sectional view of a punch press illustrating the method of making the tubular type bearing structure; and

FIG. 6 is an enlarged, broken, developed view of the strip of sheet metal with the type embossed on it.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates a part of a telegraph printer of the kind disclosed more fully in U.S. Pat. No. 3,l76,069, issued Mar. 30, 1965 to W. J. Zenner. As illustrated in that patent, a shaft supports a type wheel 186 for reciprocation and rotation to select a character for printing and for oscillation to effect printing. The type wheel 186 moves across a platen 271 and an inking ribbon 272; the type whee-l 186 is driven to engage the ribbon 272, for effecting printing, by a print hammer 293. The present invention is directed to a method of manufacture of a particular form of the type wheel 186.

In the type wheel construction with which the present invention is concerned, the portion of the type wheel 1% on which the type characters are formed is a multisided substantially tubular sheet metal member 10. The sheet metal member 10 could have any desired number of sides, depending on the number of characters required for printing a text. An octagonal type wheel is illustrated. The eight-sicled member 10 is formed from a single sheet of metal in the manner illustrated in FIG. 5, wherein there is shown a punch 11 having a suitable shank 12 for attaching it to the head of a punch press (not shown).

The entire sheet metal member 111' is formed in one stroke of the press by shearing the body of the member 10 from a sheet 13 of metal stock leaving scrap as indicated at 14land 15. In this shearing operation, the punch 11 forces the member 10 into a cavity 16 in a die block 17, cutting the member 10 from the sheet 13 and forming a registering notch 18 and tab 19 (FIG. 6). Continued movement of the punch 11 into the die block 17 forces printing character forming projections 20 into the member 10 and forms the metal of the member 10 into recesses 21 in the die block 17. In this type forming operation the sheet metal is deformed beyond its elastic limit and consequently sharp, clear, character delineating ridges 22 are embossed on the sheet metal member 10.

Simultaneously with the forming of the character delineat ing ridges 22, the member 10 is stressed, along lines 23 transverse to its length, beyond its elastic limit. This is effected by providing sharp ridges 24 on the punch 11 in alignment with the sharply angled surfaces of the die block at the lines 23. The mating surfaces of the punch 11 and die block 17 are gently curved from the lines 23, to bend the member 10 within its elastic limit in the area marked 25, (FIG. 5), to afford a flat or relatively flat area 26 adjacent. each of the printing character projections 20 and recesses 21.

When the punch 11 is retracted from the die block 17 the member 10, having been embossed with all of the character delineating ridges or type faces 22 of the type font and also having been bent beyond its elastic limit along the lines 23, will assume a configuration as shown in section in FIG. 2. Thus, the member 10 with the type faces or ridges 22 extending from its outer surfaces forms, in this case, the outer shell of an octagonal flat-sided substantially tubular printing member. The member 10 will have eight rows of type on its outer surface, in four levels, as illustrated in FIG. 6, which levels will be aligned by nesting the tab 19 in the notch 18.

In order to impart rigidity to the member 10 and to afford a means for mounting the member on the shaft 190, four octagonally shaped reinforcing members 30 are attached to the inner surface of the member 10 by spot welds 31. As shown in FIG. 3, the reinforcing members 30 are fixed to the member 10 at approximately the vertical centers of the type character printing elements 22 by applying the spot welds at the corners formed along the lines 23. All of the reinforcing members 30 are provided with central apertures 32 of a diameter to snugly fit on the shaft 190 and at least the bottom member 30 is provided with a plurality of locating holes 33 which are evenly spaced one from the other in a circle and disposed in the area between the central aperture 32 and the periphery of the member 30.

The shaft 190 has a shouldered collar 34 fixed to it by means of a pin 35. This collar is provided with a plurality of locating holes 36 which are arranged in the same manner as the locating holes 33 in the reinforcing member 30, except that, while the holes 36 are arranged with their axes the same distance from the axis of the actuating member 190 as the holes 33 and are equally spaced one from the other, the spacing between the holes 36 is slightly smaller than the spacing between the holes 33. The locating holes 33 and 36 are of the same size, chosen to snugly fit with a locating pin 37 which is fixed in a locating ring 38 that encircles and is free to move on the actuating member 190. The locating pin 37 extends beyond the upper and lower surfaces of the locating ring 38 and may be selectively positioned in the holes 33 and 36 in the reinforcing member 30 and collar 34 to provide a very fine adjustment of the type wheel 186 with respect to the shaft 190.

Near its upper end, the shaft 190 has an annular recess 39 formed in it for receiving the projecting arms 40 of a hairpin type fastener 41, the closed end of which is bent upwardly as shown at 42. The fastener 41 is wedged between the upper surface of the recess 39 and an annular spring washer 43 which encircles the actuating member and presses the type wheel structure 186, comprising the member and its reinforcing members 30, firmly onto the collar 34.

Although a specific embodiment of the invention has been described, it will be understood that the invention is not limited to the specific embodiment but is capable of modification, substitution and rearrangement without departing from the spirit of the invention.

lclaim:

1. The method of manufacturing a lightweight polygonal type wheel comprising embossing a strip of sheet metal with a plurality of type characters, arranged in rows and columns, and simultaneously stressing the strip beyond its elastic limit along a series of equally spaced transverse lines extending across the full width of the strip intermediate the rows of the type characters, all in a single continuous embossing operation, to cause the strip, following embossure, to assume a closed, polygonal, tubular configuration, with the ends of said strip adjoining each other along one corner of the polygon, with each row of embossed type characters extending along one side of the polygon and with said transverse lines extending parallel to the axis of the polygon at the corners thereof, and joining the free ends of said strip to complete the type wheel.

2. The method of manufacturing a lightweight polygonal type wheel, according to claim 1, including the cutting of complemental alignment tabs and recesses in the opposed ends of the strip, during the embossure operation, to facilitate accurate alignment of the type characters in the completed type wheel.

3. The method of manufacturing a lightweight polygonal type wheel, according to claim 1, in which bending of the portions of the metal strip adjacent said transverse lines is held within the elastic limit of the metal to afford flat surface areas around each of the embossed type characters.

4. The method of manufacturing a light weight polygonal type wheel, according to claim 1, including the additional subsequent step of mounting a plurality of relatively thin, flat polygonal reinforcement members within the closed polygonal tube formed by said sheet metal strip.

5. The method of manufacturing a lightweight polygonal type wheel, according to claim 4, in which said reinforcement members are of sheet metal, including welding each reinforcing member to said strip at the corners. 

1. The method of manufacturing a lightweight polygonal type wheel comprising embossing a strip of sheet metal with a plurality of type characters, arranged in rows and columns, and simultaneously stressing the strip beyond its elastic limit along a series of equally spaced transverse lines extending across the full width of the strip intermediate the rows of the type characters, all in a single continuous embossing operation, to cause the strip, following embossure, to assume a closed, polygonal, tubular configuration, with the ends of said strip adjoining each other along one corner of the polygon, with each row of embossed type characters extending along one side of the polygon and with said transverse lines extending parallel to the axis of the polygon at the corners thereof, and joining the free ends of said strip to complete the type wheel.
 2. The method of manufacturing a lightweight polygonal type wheel, according to claim 1, including the cutting of complemental alignment tabs and recesses in the opposed ends of the strip, during the embossure operation, to facilitate accurate alignment of the type characters in the completed type wheel.
 3. The method of manufacturing a lightweight polygonal type wheel, according to claim 1, in which bending of the portions of the metal strip adjacent said transverse lines is held within the elastic limit of the metal to afford flat surface areas around each of the embossed type characters.
 4. The methOd of manufacturing a light weight polygonal type wheel, according to claim 1, including the additional subsequent step of mounting a plurality of relatively thin, flat polygonal reinforcement members within the closed polygonal tube formed by said sheet metal strip.
 5. The method of manufacturing a lightweight polygonal type wheel, according to claim 4, in which said reinforcement members are of sheet metal, including welding each reinforcing member to said strip at the corners. 